Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at August 24, 2016

The human body is mostly made up of fluid, but when water and other fluids accumulate in the wrong places they can cause edema, a medical condition defined as swelling tissues. Angioedema is a specific type of edema that occurs in a few specific places. Since there are many different causes of angioedema, treatment depends on determining and managing the condition that is causing the problem.


Definition & Facts

Angioedema is any type of edema that happens in the lower layers of the skin, which are called the dermis, any mucous membranes in the body, or the subcutaneous tissues that lie right below the dermis. Angioedema primarily causes a rapid collection of fluid in tissues, causing them to swell up quickly.

There are two primary classifications of angioedema. It can either be an acquired angioedema case, caused by another health problem or allergen, or a person can have hereditary angioedema which is a genetic disorder.

Symptoms & Complaints

Angioedema is any type of swelling that happens in the skin, but it most commonly happens in a few areas of the body. The most typical location for angioedema is the face, and the mucous membrane linings of the tongue, lips, and nasal cavities can also start to swell. Other common areas include the hands, neck, genitals, and lower limbs.

The swelling caused by angioedema can be very rapid, occurring in just a few minutes, or it may slowly develop over several hours. Sometimes patients with angioedema do not feel any discomfort, but it can cause a sensation of itchiness or swelling. Angioedema may be accompanied by hives on the skin, or it can also occur alongside abdominal cramps if the angioedema happens in the mucosal linings of the gastrointestinal tract.

In severe cases of angioedema in the throat, neck, mouth, and nose, breathing airways can become obstructed, causing difficulty breathing. Most symptoms of angioedema are not dangerous, but obstructed airways can potentially be life threatening.

Angioedema symptoms normally develop rapidly and do not recur among people with acquired angioedema, but those with the hereditary kind tend to have regular episodes of slowly developing angioedema every few weeks or months.


There are a variety of issues and conditions that can affect the possibility of a person getting angioedema. Patients with acquired angioedema most often get it after an allergic reaction. Even a mild allergic reaction can trigger histamine chemical releases that cause rapid angioedema. Common allergens that cause angioedema include animal dander, certain foods, pollen, and bug bites, but there are many other potential sources of allergic responses.

Angioedema can also be a side effect of taking medications such as blood pressure medicines (antihypertensive drugs), antibiotics, and some types of painkillers. People who have other health problems such as lupus, lymphoma, or leukemia, may all develop angioedema as a symptom of their health condition. However, not all types of angioedema are caused by illnesses and allergies.

A rare genetic mutation can cause families to pass down hereditary angioedema. Mutations among the SERPING1 gene or the F12 gene can cause abnormal C1INH protein levels that damage cells and increase the chance of fluid traveling out of blood cells and into other bodily tissues.

Diagnosis & Tests

Because it is often so physically apparent, there are not that many tests needed to diagnose a case of acquired angioedema. Normally, a person is diagnosed with angioedema after a physical examination confirms that they are suffering from swelling in the areas affected by angioedema. Most steps of diagnosis then focus on determining the underlying cause of an angioedema attack.

Tests to examine a patient's complete blood count, liver enzyme levels, renal function, and enzyme balance are routinely done during an angioedema diagnosis to rule out other conditions and narrow down the possible causes of angioedema. A blood test can reveal elevated levels of mast cell tryptase that is the hallmark of an allergic reaction that is inducing angioedema.

It is slightly more difficult to tell if a patient is suffering from hereditary angioedema because doctors often just assume that a patient is coming into contact with whatever allergen could trigger an acquired angioedema issue. Normally, it is only suspected if a patient is regularly having angioedema attacks and does not respond to traditional treatments. In order to diagnose a person with hereditary angioedema, a doctor can do a genetic test that determines if they have the genetic mutations that lead to angioedema.

Treatment & Therapy

Most cases of angioedema are merely an allergic attack, so the basic treatment is normally just taking an antihistamine medication and avoiding the allergen in the future. Antihistamines do not work immediately, but cold compresses can help to ease pain and itching until the medication slowly reduces swelling levels. Corticosteroid therapy can also be helpful for people who have angioedema due to other medical conditions.

If a person has extremely severe, life-threatening angioedema and anaphylaxis, an epinephrine shot should be applied immediately to counteract the allergic response and allow the patient to breathe again. Inhaler medicines, such as the ones used to treat asthma, can also help to open airways and make it easier to breathe.

If the angioedema is caused by a medication, the medication should be discontinued if possible.

In cases of hereditary angioedema, patients may be treated with a supplement of the C1INH proteins that their body lacks through intravenous treatment.

Prevention & Prophylaxis

For people with known allergies, avoiding any exposure to these allergens is the best way to prevent angioedema from occurring. If a patient experiences the onset of angioedema, prompt medical treatment can stop an attack of angioedema from escalating to dangerous levels.

Taking an androgen medication that increases certain enzyme levels can also help to prevent further angioedema attacks. Since hereditary angioedema can be triggered from exposure to certain materials, such as alcohol and ibuprofen, avoiding triggers can also help to reduce symptoms.